[Mechanical performance of non slotted small diameter nails of Gross and Kempf].

The goal of this study was to evaluate the mechanical properties of closed section small diameter Grosse-Kempf tibia nails. This type of implant has been advocated for an unreamed nailing of open tibia fractures in order to avoid further damage of bone blood supply and an increased risk for compartment syndrome. Static and dynamic tests were performed on 9 and 10 mm nonslotted Grosse-Kempf (G-K) and Russel-Taylor (R-T) nails.

Effects of sCD23 on proliferation of leukemic cells from a patient with chronic myelogenous leukemia during blast crisis.

The present study has attempted to further delineate the growth factor requirements of peripheral blasts of a patient with CML in acute phase. Phenotypic analysis of leukemic blasts from this patient before culture has shown a homogenous population of CD34+ cells at the onset of blast crisis. In the second and third samples the percentage of CD34+ DR+ blast cells decreased slightly and up to 32% of cells in the third sample expressed the CD19 antigen.

Aneurysmal cyst of the proximal radius: resection and free vascularized fibular bone graft.

We present the case of a 22-year-old woman with an aneurysmal cyst of the right proximal radius, treated by resection and a free bone graft (microvascular fibular transfer), without recurrence after 4 years. Over a 4 month period, there was a rapidly expanding and lytic lesion found in the radius. There were symptoms of elbow and wrist pain and early radially innervated muscle weakness.

[Comparison of mechanical qualities of cortical bone preserved by various freezing methods].

The purpose of this study was to compare the mechanical properties of the human cortical bone following three deep-freezing techniques: addition of D.M.S.

Enrichment of human marrow T-cell precursors by complement-dependent cytotoxicity with monoclonal antibodies and Percoll Gradient centrifugation.

Attempts to enrich and characterize human marrow T-cell precursors have been performed using discontinuous Percoll gradient centrifugation, phenotypic analysis of cells with monoclonal antibodies (Mabs), and T-cell colony-forming capacity. Marrow cells were extensively depleted of T cells and separated into seven fractions. The depletion was performed with the following Mabs: CD6 (MBG6 or RFT12) + CD8 (RFT8), CD2 (D66) + CD8 (RFT8), and CD6 (RFT12) + CD8 (RFT8) + CD7 (RFT2).

Agar human T cell colony growth promoted by a B + null cell-derived lymphokine distinct from IL 2.

Human T cell agar colonies can be grown under PHA stimulation from either mature T cells or their E rosette-negative (E-), OKT3- peripheral blood and bone marrow precursors. Colonies comprise a majority of mature E+, OKT3+ cells and a minor (5 to 10%) population of immature E-, T3-, T8-, T4-, DR+, T10+, RFB1+ cells, which upon replating in subculture, can generate secondary colonies of OKT3+, E+, OKT4+, OKT8+ cells. Secondary colony formation can serve as a test for growth requirement of colony precursors, because it depends on the presence of both PHA and a colony-promoting activity (CPA) recovered in PHA-stimulated B + null or T + adherent cell supernatants.

Characterization of the T lymphocyte colony-forming cells and evidence for the acquisition of T cell markers in the absence of the thymic microenvironment in man.

The nature of the T colony-forming cell (T-CFC) in agar is still controversial. We present evidence that blood mononuclear cells depleted of T cells by E-rosetting or lysis with OKT 3 and complement can give rise to E+ OKT 3+ colonies in the presence of supernatants of PHA-stimulated lymphocytes (P-SUP) containing a cell growth factor. Both OKT 4+ (67%) and OKT 8+ (32%) cells were found in the colonies, and less than 10% of these cells were Ia+.

The nature of cell interactions during phytohemagglutinin-induced T-cell colony formation.

When a constant number of peripheral human blood mononuclear cells (MC) are seeded in an agar overlayer on top of a cell free underlayer supplemented with 100 microgram phytohemagglutinin (PHA), the number of colonies formed is dependent on cell concentration with respect to both the overlayer and total culture volumes. These results support the view that during PHA-induced colony formation cell cooperation between T-colony forming cells and a population of cooperating cells (CC) is mediated by diffusible soluble mediators. They also indicate that the effect of such mediators is dependent on concentration and not only on total amount in the culture.

Trochanter bone marrow: a source of normal human colony forming cells.

In vitro studies of human hemopoiesis are often limited by the availability of normal bone marrow. We have overcome this difficulty by taking advantage of the bone marrow fragments removed during total hip replacement. We report here a comparative study of the colony forming capacity of trochanter and sternal or iliac crest marrow from five hematologically normal donors.